According to the ( 2006 ) Mercury Milan Owner Guide :
With engine oil filter change :
The 3.0 liter Duratec , V6 engine takes :
( 5.7 liters / 6.0 U.S. quarts of 5W-20 )
4.5 quarts
( 6.0 quarts ) with engine oil filter change , according to the Owner Guide
Bottom of the engine on the oil pan.
The 2010 Milan requires 5W20 Synthetic Blend (Motorcraft preferred or equiv.)
Drain plug is located on oil pan located on bottom of engine.
According to the 2006 Mercury Milan Owner Guide : For the 3.0 litre " Duratec " V6 engine : With engine oil filter change : ( 6.0 US. quarts / 5.7 litres of 5W-20 )
If it is a V6 about 6 Quarts with a new oil filter.
These engines take about 4 quarts of oil.
The 1998 Mercury Tracer owners manual shows : 4.0 quarts ( 3.8 liters ) with oil filter change
4.5 quarts / 4.25 liters , with engine oil filter change ( according to the Owner Guide )
4.5 quarts ( 4.25 liters ) with engine oil filter change , according to the Owner Guide
There is a clearly labeled cover over the general area of the oil filter behind the cross member on the underside of the car.